What is CVE-2026-23736?

CVE-2026-23736 is a high-severity vulnerability in Lxsmnsyc Seroval, classified under Improperly Controlled Modification of Object Prototype Attributes (Prototype Pollution). CVSS score: 7.3/10. Published 2026-01-21.

How severe is CVE-2026-23736?

High severity. CVSS v3 base score is 7.3 out of 10.

Prototype Pollution in Lxsmnsyc Seroval

CVE-2026-23736

seroval facilitates JS value stringification, including complex structures beyond JSON.stringify capabilities. In versions 1.4.0 and below, due to improper input validation, a malicious object key can lead to prototype pollution during JSON deserialization. This vulnerability affects only JSON deserialization functionality. This issue is fixed in version 1.4.1.

Vulnerability class: Prototype Pollution

Published 2026-01-21 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.3 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L.

EPSS exploit prediction

EPSS: 0.003 (19.7th percentile), scored 2026-10-01.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 20th percentile — 19.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: +0.000

Affected products

Lxsmnsyc Seroval — versions < 1.4.1

Weakness classification (CWE)

CWE-1321 — Improperly Controlled Modification of Object Prototype Attributes (Prototype Pollution)

References

github.com/lxsmnsyc/seroval/security/advisories/GHSA-hj76-42vx-jwp4 (Vendor Advisory)
github.com/lxsmnsyc/seroval/commit/ce9408ebc87312fcad345a73c172212f2a798060 (Patch)

Frequently asked questions

What is CVE-2026-23736?: CVE-2026-23736 is a high-severity vulnerability in Lxsmnsyc Seroval, classified under Improperly Controlled Modification of Object Prototype Attributes (Prototype Pollution). CVSS score: 7.3/10. Published 2026-01-21.
How severe is CVE-2026-23736?: High severity. CVSS v3 base score is 7.3 out of 10.